The present invention relates to an arrangement which enables data to be exchanged between the memories and the processing devices of a computer.
Arrangements of this kind known at the present time are specific both as to the technology of the memories employed and as to the computer processing units which make use of the memories. Similarly, arrangements for exchanges between processors depend entirely on the processors.
At the present time, the technology used to produce central memory units for computers in evolving rapidly both from the point of view of performance and from the point of view of modes of operation.
The result is that whenever new technology appears on the market it is necessary, if it is desired to use the new technology, to modify all the logic elements which perform exchanges between the memory unit and the processors using the unit. In fact, corresponding to each new kind of technology which appears there is a new mode of operation and, in particular, different timing for the signals exchanged.
So that the invention may be better understood, it will be mentioned here that a processor is the part of the computer in which processing takes place and which contains the control elements and the elements for arithmetic and logic calculations. In small and medium size computers, the processor is represented by the processing section of the central unit. The central unit also includes the central memory and the connecting channels to the peripherals. In large systems, one or more processors are independent, as also are a number of central memory units and input/output controlling units.
Also, for obvious economic reasons, it is helpful to use the same memory unit for different processors. However, generally speaking, because of the differing modes of operation of processors, it is necessary to make extensive alterations to match up the interface elements each time a new processor is connected to a memory unit for which it was not originally intended.